Pdf an introduction to cell motility for the physical. An introduction to cell motility for the physical scientist. Mechanism for cell shapeliness decoded from fish scales. Tutorial an introduction to cell motility for the physical. Movement at the molecular level mit opencourseware. Actindependent motile forces and cell motility louise p cramer, timothy j mitchison and julie a theriot university of california, san francisco and whitehead institute for biomedical research, cambridge, usa force arising from actin polymerization and myosin activity drives a number of different actinbased cell movements. Departments of biochemistry and of microbiology and immunology, beckman center, stanford university school of medicine, stanford, ca 943055307, usa. The coordinated movement of crawling cells depends on the proper spatial and. The shape of motile cells is determined by many dynamic processes spanning several orders of magnitude in. Here we combine experimental manipulations and mathematical modeling. Balance between cell substrate adhesion and myosin initiation. Certain cell types are specialized for locomotion, e. Actinmyosin network reorganization breaks symmetry at the cell.
Meeting report a hitchhikers guide to cell biology. The grampositive bacterium listeria monocytogenes is a facultative intracellular pathogen capable of rapid movement through the host cell cytoplasm1. Julie theriot attended college at the massachusetts institute of technology, graduating with degrees in physics and biology. Microparticle traction force microscopy reveals subcellular force exertion patterns in immune celltarget. Mechanism of shape determination in motile cells ncbi. These pathogenic bacteria grow directly in the host cell cytoplasm. Theriot actinbased cell motility is a complex process involving a dynamic, selforganizing cellular system. Here, we use live microscopy and statistical modeling to demonstrate that l. With colleagues rob phillips, jane kondev, and hernan garcia, she has published a textbook, physical biology of the cell, exploring the applications of mathematical and physical modeling in cell biology. Myosin ii contributes to cellscale actin network treadmilling via.
Physical biology of the cell 2nd edition rob phillips. Theriot s 286 research works with 11,557 citations and 6,352 reads, including. Cameron l a, giardini p a, soo f s and theriot j a 2000 secrets of actinbased motility revealed by a bacterial pathogen nat. An introduction to cell motility for the physical scientist daniel a fletcher1 and julie a theriot2 1 department of bioengineering and biophysics program, university of california at berkeley, berkeley, ca 94720, usa 2 departments of biochemistry and of microbiology and immunology, stanford university school of medicine, stanford, ca 94305, usa. Theriots research focuses on how interactions at the molecular level determine cell behavior, in particular, how cells change their shape or direction of movement. Within hours of listeria monocytogenes infection, host cell actin filaments form a dense cloud around the intracytoplasmic bacteria and then rearrange to form a polarized comet tail that is associated with moving bacteria. If cells display specialized cytoskeletal structures, researchers have options for speeding the rescuers or blocking the invaders in a targeted way. Interview open access why are bacteria different from eukaryotes. Theriots 286 research works with 11,557 citations and 6,352 reads, including. In order for a stationary cell to initiate motility, the symmetry of the system must first be broken by. Theriot, journalphysical biology, year2004, volume1 12, pages t110. Microparticle traction force microscopy reveals subcellular force exertion patterns in immune cell target. Apr 21, 2015 symmetry breaking and motility initiation are required for many physiological and pathological processes, but the mechanical mechanisms that drive symmetry breaking are not well understood. Actin microfilament dynamics are intimately involved in all of these common types of cell motility, but the mechanisms of force transduction and movement are still poorly understood.
After four years as a fellow at the whitehead institute for biomedical. It maps the huge and complex landscape of cell and molecular biology from the distinct perspective of physical biology. The polymerization motor theriot 2000 traffic wiley. For a cell to maintain overall directionality in its movement, it must be able to regulate the functioning of the polymerization motor in space and time. While the role of myosin ii in the rear of motile cells is conventionally associated with. The rate of actinbased motility of intracellular listeria. Theriots research works stanford university, ca su and.
Protrusive motility in biological systems can be initiated by local catalysis of actin polymerization, for example at the leading edge of lamellipodia and filopodia in crawling amoeboid cells7,8. But recent findings by hhmi scientists and others reveal that the cytoskeletal architecture differs significantly from cell to cell. The actin cytoskeleton in animal cells must also drastically rearrange in a cell cycle dependent manner in order to perform cytokinesis. Involvement of profilin in the actinbased motility of l. Fish keratocytes break symmetry spontaneously, in the absence of external cues, with myosindriven actin flow preceding rear retraction. Wang interpreted this flux as trends in cell biology vol. Cell motility is a fascinating example of cell behavior which is fundamentally important to a number of biological and pathological processes. Cell motility and migration kunchun lee biophysics, uc davis edward banigan physics, upenn gareth alexander physics, upenn.
The nucleationrelease model of actin filament dynamics in. Actin filament dynamics in cell motility springerlink. Oct, 2017 taking the average halflife of a protein to be about 1 day cambridge et al. Fish keratocytes are among the fastest moving animal cells, and their motility machinery is characterized by extremely. Listeria monocytogenes celltocell spread in epithelia is. Feb 05, 2019 to complete celltocell spread, the recipient cell engulfs the bacteriumcontaining protrusion, thus giving l. Actindependent motile forces and cell motility sciencedirect. Mar 29, 2016 theriot s research focuses on how interactions at the molecular level determine cell behavior, in particular, how cells change their shape or direction of movement. The rate of actinbased motility of intracellular listeria monocytogenes equals the rate of actin polymerization.
Research open access a geneexpression program reflecting the. Experimental problems initially limited our understanding of this type of motility, but the use of a model system derived from a bacterial pathogen has led to a breakthrough. It is based on a complex selforganized mechanochemical machine consisting of cytoskeletal filaments and molecular motors. After four years as a fellow at the whitehead institute for biomedical research, theriot moved to stanford university school. Spatially correlated contraction and actin depolymerization in motile cells has been shown to be. We have devised a cell free extract system capable of faithfully reconstituting l. Actin based motility is also used in cellular motility. Rob phillips, jane kondev, julie theriot, hernan garcia physical biology of the cell is a textbook for a first course in physical biology or biophysics for undergraduate or graduate students. Apr 24, 2020 biology is changing at a dizzying pace. Motile cells navigate complex environments by changing their direction of. How listeria spreads from cell to cell courtesy of julie theriot. Jan 11, 2002 from the polymerization motor to cell motility. The phasedense streaks behind the bacteria are the actinrich comet tails. Immune cells and neurons put their legos together in completely different patterns, says hhmi investigator julie theriot, who studies cell motility at stanford university.
In many tissue cells, the capacity for locomotion is normally repressed, but can be activated by wounding or oncogenic transformation. The advent of new technologies such as superresolution microscopies and dna sequencing, to name but a few, are making it possible to query the inner workings of molecules, cells and multicellular organisms in ways that were previously unimaginable. If cells display specialized cytoskeletal structures, researchers have options for. Same physics as cell crawling actin and listeria motility cdc. Persistent directional cell locomotion requires an asymmetric distribution of growing actin filaments, a classic example of cell polarity911. Mitchison the actin cytoskeleton is intimately involved in the motile behaviour of animal cells. Theriots 286 research works with 11600 citations and 6455 reads, including. Actinmyosin network reorganization breaks symmetry at the cell rear to spontaneously initiate polarized cell motility. Mechanics and dynamics of rapid cell motility duration. Most animal cell types possess the capacity to move over or through a substrate, and cell locomotion plays a key role in both normal physiology and disease. Julie theriot explores the mechanics and dynamics of cell selforganization and movement in a variety of cell types ranging from bacteria to fish skin cells. Physical biology of the cell a handson course in the theoretical dissection of biological phenomena september 18 to october 8, 2016 hernan garcia uc berkeley rob phillips caltech olga dudko uc san diego greg huber kitp, uc santa barbara jane kondev brandeis university julie theriot stanford university. Theriot, alex mogilner the balance between cellsubstrate adhesion and myosin contraction determines the frequency of motility initiation in fish keratocytes. Physical biology of the cell marine biological laboratory.